Power amp ONLY profiles?

  • I am pretty sure, you can profile the power amp very easy like a normal direct profile, only using effects loop return instead connecting kemper send to amp input. Of course a di-box between speaker out and cab is needed to get the signal back to Kemper return.


    So same setup as making direct profiles of an amp, but bypassing the preamp. Kemper should capture the flavour, saturation and character correctly.

  • Exactly, it's quite simple, instead of plugging in the front input of the amp, you plug in the Return of the FX loop of the amp and you treat it exactly like a direct profile.


    There's actually nothing to do with the amp EQ because they no longer work as on almost all amps they're tied to the pre amp and you're tapping the signal bypassing the Preamp. Not sure if the amp volume will still work.


    So guitar> Kemper Front input to help set levels then Kemper send to TUBE AMP FX lOOP Return. Speaker out into DI to Kemper return.

  • Exactly, it's quite simple, instead of plugging in the front input of the amp, you plug in the Return of the FX loop of the amp and you treat it exactly like a direct profile.


    There's actually nothing to do with the amp EQ because they no longer work as on almost all amps they're tied to the pre amp and you're tapping the signal bypassing the Preamp. Not sure if the amp volume will still work.


    So guitar> Kemper Front input to help set levels then Kemper send to TUBE AMP FX lOOP Return. Speaker out into DI to Kemper return.

    Thanks for sharing the HT-5 power amp profile - still using it!


    I hope others are encouraged and will try it out with what they have at hand ... and share there power amp profiles :thumbup:

  • The overwhelming majority of Profiles (Studio, Merged, and Direct Amplifier types) do include the power amp.


    Direct Preamplifier Profiles are the only type that do not icude the power amp, and there are relatively few of those.


    Exactly!


    Notwithstanding the practical possibility of profiling only the power stage...


    I am not even sure why someone would want to profile only the clipping/distortion of a tube amp's power stage. I am pretty sure, approximately zero musicians and music lovers have heard the sound of (for example) only the 4 EL-34s/6550s and output section of a Marshall 1959SLP, being unnaturally (artificially) sent into clipping. Unnaturally -- meaning that the signal would not contain the all important contributions of the dual triode preamp tubes (12AX7s) and cathode follower, tone stack, phase inverter, etc...you know, all those critical tone generators, shapers and filters which make a Marshall sound like,... well, a Marshall guitar amp.

    Substitute any make/model in this example.

  • Include, yes. But it seems most are relying on primarily the preamp stage for the distortion for the profiles.

    That depends on the amplifier profiled, and the amp settings used by the person doing the profiling.


    But, even with vintage amps (with no master volume control) the only way to get power amp distortion is to use a large amount of preamp output. and, those input circuit designs tend to distort when the preamp is turned up.

  • Hello Bob,


    I am not arguing. Nor am I being cheeky or sarcastic. Indeed, you have put forth a valid possibility in profiling. However, I think, perhaps, you are putting too much stock into the sonic characteristics of a tube amp's output stage. The output tubes are meant to cleanly amplify the input signal. Yes, the output tubes of a tube guitar amp can be coaxed into soft-clipping. However, the results of the output tube clipping characteristics cannot be separated from the input (feed) signal. Mostly, the effect of the output tubes is in how the amplified signal, sent to a guitar speaker, "feels" and reacts...rather than sounds...to a first approximation. In any case, the issue is rather moot...in the sense that in your scenario, the profiler would be capturing the primary essence of the Mixer signal, being amplified and perhaps clipping the output stage. It will NOT sound like a guitar amp, because the notional Mixer does not have the preamp section of a guitar amp. I mean, it will sound like something...but probably nothing you would be interested in playing.


    Nevertheless, it might be an interesting experiment, and who knows, it might produce something musically useful for the guitarist. Never know until it is tried, I suppose. :)


    Cheers,

    John

  • I made a profile of the power amp of my Koch Studiotone. That sounds pretty good in combination with a preamp pedal like a Victory V4.


    Next, I will do a direct profile of the power amp of my Dirty Shirley.

    Hello Workingtitle,


    Just curious...what did the profile sound like, on its own, with no external preamp or stomps, and no addition of internal Kemper stomps (i.e., A, B, C, D all off)?

  • Just curious...what did the profile sound like, on its own, with no external preamp or stomps, and no addition of internal Kemper stomps (i.e., A, B, C, D all off)?

    It sounds a little lifeless and flat alone. But in combination with the Victory V4 Preamp it becomes something.


    So far I've only done one profile. The Studiotone has an unfiltered direct out, which sits behind the power amp. So it's pretty easy to make a profile from the power amp.


    How the profiles of the Dirty Shirley power amp will be, will be exciting. I always liked the preamp pedals best with the power amp of this amp.

  • I'll run a profile through my effects loop on my Uberschall and upload it to the exchange, I'll let you guys know when it's done, this will be accomplished using the Radial Headload and pull from the pre-eq output. That should provide as close to zero color as I can come for capturing the power amp only.

  • I am new here but wouldn't you know, this would be the first thread I go to :)

    I have a little experience with tube power amps. I can't and will not say the name but, I own a website that sells IRs that have loads of them made with different tube power amps as well as SS.

    A tube power amp, depending on what model of amp, can be as much as maybe 50% of the tone of the amp. Every tube power amp or power amp section of an amp is different. They each have their own character. Some add huge amounts of mojo while others (like Mesa) do very little.

    Making IRs with tube amps and capturing that character is a bit tricky. We spent countless hours on getting it right. Lots of trial and error. We even did amps with different tubes and it is possible to hear, although you have to have a very discerning ear, but afterwards decided it may just be overkill and we ditched that idea.

    Concerning the Kemper and capturing just the tube power amp section to me sounds intriguing. My guesstimate would be that 6L6 types would not be as good but EL34 and EL84 might be interesting.

  • Yeah, I get it!

    I spent many of years using mostly tube preamps into power amps of all kinds. I've used different SS as well as tube power amps and heads as power amps. Let alone the "feel", a power amp definitely imparts a frequency response to your tone. One of the best ways to understand this is to get a Marshall DSL and a Mesa Rectifier. Try each amps preamp into the other amps FX return. You will real quickly find out which power amp sounds anemic. Hint: it's not the DSL.